Reamer



Oct. 13, 1931. w. H. EVANS Filed Aug. 28, 1929 Patented Oct. 13, 1931 BEAMER i" .Applieation'l'cdihugust 28, 1923erSerialjoa'hs ff n' l surface ofthe valveseatfis'so 'alected by car.- honthat fa veryhard scalelis formed thereon andthis must ,broken rup, and removed be: fore thev reamng fftool canl ,be used. ,-1 With .29 most types of reamersthis requires-the oftwof-too1s -and neeessitates 'twoeopelatiQIlSg Another diiicu'lty: that mostfreamers; chat.-r ter-to suchl anjfextentthat theseat is left in 7.a

' rough; condition. which can be' remediedlonly by. grinding? l fNowm-my Patents 15863D65611 disclose a reamer whieh willlovercome .f manyf ofthese .difficulties pending;apprcauonrseeai ne. 14652.58, vfil@ November4,l926 disclosed a reame'r con- 'taining' still Y Yfurther improvements 'whereby the *scale t 'caribe rerrroi'ed *andl thelvalvegseat reamed in a tool.

these :tools on, usualsizesgof Valve ,Seatshl 'have found that recently .in somey small -Slz's of motonsthe valve, .seats fare so; decreasedin dameterthat my prioriy c'oustructionsCalklllbty readily be. used, although thelpriniplesgare as readilyadaptable to smallsizespf reamr Vvastolargesizes.A Y Accordingly vone oi the. rprincipal ioloj eciis ofciny present inventienisthe proysionfof a relatively small reamerlhayingytlie samexdesrable features, as setpfonth lin my prior rpat- -ents'and applications l Another object yis theV p. @esibirsi @einer of this type which can' be used with astandarl operati-0.11; witliihe me o 1min-be ,seenthat the teetlhfie mi i7', 21

offimprovedjdesign. v Another object is theprovision yof .rim-l proyedtype ofvalve seatreamer vhaving anr` exceedingly hard cutting edgew'ithA the reamerhead constructedlto prevent4 chipping of said edge. A

Another obj ect is the kprovision of emeroteca anewfe'afesf'ihe meer."

tion will-be -apparent from the consideration ofA jthe detailed description `.taken with rfthe accompanyingdrawingsWhereinFg? 1 is a fragmentaryvertical-sectionalview showing my improved reamer in. use kkwith a standard. type andsizerofspindle'.Yv

s Fig. 2 vis av face` View of ythe'reainer u ing the cutting blades orteethl c Fig Sis: a fragmentary sectional View.Y

r-vFig ,ellis an elevationalviewjl "j j" 1 n c Fig.'v.5 is anenlargedvview showinga detail ofthe .cuttingblades.` f

emplify one embodiment of the rlventollythe learner includesa,headkv lOysth an interior j i longitudinally .disposed taperedl opening .adaptedto engage .the tapered face' 11; ,of the llsuaireamerpilot cit-,spindle 12. The pilot isgequippedwiththeusual centering piece' 13 and is in all-:respects the, samefas A.thepresent standardreamer pilot. i Ilhehead,.10 hasintegraltherewth, 'a frus;

manner Ato' secure certain` g definite Y desirable Y' results, and there is ino; part of Ythe structure 11er any detail 0f construction which doesn@ yovntrloiite@to the .unique'opemtiqn of 13h@I 00.1 .asaW-holemr` P H ,carried thereby areall formed a particular v i and rr22 an@.Provided with clorrugatrns 16a and 17a, 21a and 22a respectively, Whilefthe lfront 'faces' of the reaming-teeth are smooth.

' Thismeans'thattheteeth 1 6,v 17., 21,' and 22 are designed to break up andl remove the 'carpri'neipally` instrum,ental` kv,performing, the

teaming operation per se.A 2 t f @prima ,sermons resine *uiejsmooih 95 bm'l'llrn and V,high carbonfcontent steel on l 'they Valve seat Whilethe ,reaming teeth are *o :lo Referring 110W tothe, drawings which ex a face teeth are arranged with sucient resiliency so that they can ride over the hard scale while the grooved teeth are made more rigid to hold their position and cut through the scale. This is obtained in the present embodiment by the following construction.

At both sides of each smooth tooth the coni-y cal portion of the frame or body of the rea-mer is cut through to form a slot 26 and with the number of teeth shown these slotsare sin` in i number. Instead of forming'the inside annular surface of the cone portion so as to fit` by, thecharacter 28) between the groovedteeth is unslotted. This sostrengthens this portionV of the conethat it is flexed with difficulty and so thatwith normal pressureY on the reaming teeth, the grooved teeth can cut through the scale and remove it before any substantial work is performed by the smooth face teeth.l Y

The teeth are inclined lat varying angles to the radius ofthe reamer so that adierent cutting angle is assumed by each one, and this tends to .prevent chattering and also Yservesto preserve alsmooth surface at all stages of the .reaming operation;` The top surface ofthe cutting edges has suficient slant ordrop; (about three mills) so that they can cutwith sufhcient depth lto obtain adequate cutting speed* but will not penetrate to such depth as topromote chattering. The drop also maintains thecutting edge sharp for a greater length of time than if a greater drop from the. front to therear edge existed. The teeth all lie backwardly andthetool as a whole'has sufcientA resiliency in the cone portion which holds theteethso that even if unusually great pressure is applied to the tool chattering will not result.k

In order. that those skilled in the art will have a complete understanding Vof my improved reainer Ik wish to point outthat it is formed from a single piece of mildsteel, so that an integral" structure is obtained throughout. The'shape isobtained by suitable machine operations of a type which willbe readily understood. When the tool has been completed it is pack hardened throughout with the. result that a very .hard .cutting edge is obtained, but cracking and chipping of the `teeth or other parts of the tool areabsolutely prevented bythe underlying softer metal. Fig. 5 illustrates the hardened condition of the teeth. The inside portion' ofthe teeth indicated in the enlarged View by the character 29 is soft. On both sides of this soft area the tooth is hard and accordingly it can be resharpened to its very base and still the same cutting edge can be obtained.

I VwishA to callattention to the fact that my present type of reamer hasa longer life than the rearners of the prior art. Before the inventionof my priorreamer, it was customary to employ a solid substantial construction of high grade tool steel,'and then to "prevent the concomitant chipping of the hard cutting edge, the reamer was tempered byv drawingitdown-*toabout a straw color. The reamer so produced did not chip, but neither did it have a long lifev when usedv on the relatively hardmetal of the valve seats.

With frequent resharpening, however, fairy results as far as life is concerned, were obtained.I

' Now -I `obviated these dificulties in my prior inventions referred to, by stamping the reamer'vhead from sheet metal so as to have a normal inherent resiliency. It was then possible to case harden the cutting edge to a glass hardness, and ldepend asa safety factor, on the vspring of the metal head to relieve unusual strains and so prevent the subjection of the cutting edge to such strainsV as might cause chipping. So unusual were the results so secured, thatfIhave used many of my old reamers to renew as many as 2500 seats, ascomparedv to an laverage of not more than tenor twenty for old reamers. With the present reamer constructed from a solid piece of milkl steel and -thenpack or case hardened, I have obtained similar results. It is the entire construction fwhich enters' into this result. lThe resiliency obtain-ed by the shape of the headis a feature of greatimportance, also aidedby the angle at which `the teeth are set,the use of two 'distinct sets of teeth on the two hemispheres spiralledfin opposite directions. Although y'generally I prefer to pack harden the entire reamer, similar results may be obtained by hardening only the blade portion thereof.

The present invention operates in substantially the same way as the reamer described in my co-pending application. The spindle or .handle is inserted in the reamer head and the reamer teeth brought to position against theY valve seat. By' turning the tool in a clockwise directionv the grooved teeth immel'diately operate to remove the hard outside Vsurface of the vseat,`-the`smooth teethin the meantime :flexing sufliciently to ride over the hardsurface. This continues until met-al is reached soft enough for the smooth teeth to make an impression after which all 'of the teeth operating at differentangles in the manner described cut a smooth finish seat. This is done ina single operation in the manner set forth. f

The present embodiment of thev reamer is machined inits entirety 'from a solid vpiece'k of metal and this is the/preferred construction but it will be understood that some of the features of theA invention are applicable.' to areamermade in die'rent ways. .Forex ample some of these features may be incor-` porated in a reamerof'the general type shown in my'prior patents spoken of previously.

While I have described the details of the present embodimentof my'invention in order that those skilled' in the art will have a full understanding thereof, I donot restrict myf self to the constructionshown, the invention being limited only bythe scope of the vappended claims. i

Iclaimz` f l Y l. In a reamer of thecharacter described, a reamer head having a tapered longitudinal opening for friction application to a tapered shank, a portion of the opening being shaped to form a clearance withthe shank, and a plurality of teeth carried by the-head'adjacent said clearance so that such teeth may flex into said clearance when under pressure.

2. In a reamer of the character described, a reamer head with a longitudinal opening adapted frictionally'to vengage 'a tapered shank, and a plurality of teeth carried by the head, the head'being shaped in the kregion of the teeth to provide resiliency therein, and

the head opening being spaced from the shank at such point to allow theV teeth bearing Vportion ofthe head to flex inwardlyy under pressure. c v i 3. In ak reamer of the character described, a reamer head with a longitudinal opening adapted frictionally to engage a taperedv shank, a plurality of teeth designed to remove carbon scale and a plurality of teeth designed to ream a smooth finish toxa valve seat, the head being shaped in the region of the teeth to provide resiliency therein and with greater Y resiliency imparted to the reaming teeth than to the scale removing teeth, and the head being spaced away from the shank in the region of such teeth to allow the teeth bearing portion of the head to flex inwardly under pres sure.

4. In a reamer of the character kdescribed a reamer head with a longitudinal opening adapted `frictionally to engagev a tapered shank, a plurality of teeth designed to remove carbon scale, and a plurality of reamer teeth, the head being shaped in the region of said reamer teethto impart flexibility thereto and including a clearance between the head or shank in the region of such teeth to permit the samek to flex inwardly under pressure.

5. yIn a reamer of the character described, a solid reamer head having a longitudinal opening .for receiving a tapered shank, and

having one end slanting generally inwardly.; to 'forma frustro cone, and a pluralityy of teeth carriedby the coneand placed at an cone being slotted atthe sides of some'of said teeth toimpart resiliency thereto, and the ybalance of. said teeth remaining relativelyy stift and function as scale removers.

f l 6.' A reamer comprising a reamer head with y a cone shaped end having radial slots therein with alongitudinal opening for receiving a Y pilot, and a plurality of teeth carried by the cone end, said teeth being spiralled and slanted away from the directionof rotation of thereamer, the cone enddisposed with re'- spect to the' pilot lto be out of contact there- 'with' whereby -tooth supporting portions thereof may be flexed inwardly under pressure. Y

7. A reamer comprising a reamer head with a cone shaped end having radial slots ried by the cone end, said teethy being `spiralled and slanted away fromthe direcsol therein with a longitudinal opening for re-y -y 'ceiving a pilot, and a plurality of teeth care tion'of rotation of the reamer, the cone end disposed with respect to the pilot to be out'of contact therewith whereby tooth su porting portions thereof may be flexed inwar ly under l pressure, the reamer being case hardened to form a glass hard cutting edge and the position of the teeth and resiliency of the cone end of the head serving as a safety factor ,t

prevent chipping of the glass hard edge.

8. A reameras defined in claim 7 wherein somevofthe teeth are secured'to kan unslotted ing teeth than to the scale removing teeth, the

head being spaced away from the shank in the region of such teeth to allow the teeth bearing portion of the head'to flex inwardly underl pressure, said scale removing teeth being roughened on the entering faces to facilitate breaking up the scale. l o

In witness whereof, I hereunto subscribe my name this 23rd day of August,`1929.

WILLIAM H. EVANS.

- ylao angle to the path o-f movement thereof,`the .d i 

